1. Field of the Invention
The present invention relates to a motorcycle.
2. Description of the Prior Art
When a motorcycle corners, the motor banks, i.e., is inclined laterally, to produce a centripetal force which counterbalances the centrifugal force generated on the motorcycle which depends on the weight of the motorcycle and the rider, the running speed of the motorcycle, and the radius of the cornering circle. Generally, the running speed of the motorcycle is reduced when the motorcycle corners.
The applicant has proposed a motorcycle capable of cornering at high speeds in races or other high-speed occurrences. The proposed motorcycle has a motorcycle wheel having a round tire and a rear frame supporting a rear wheel having a flat tire. The front and rear frames are interconnected in a longitudinal direction of the motorcycle. The front frame can be inclined laterally about the coupling shaft by which the front frame is coupled to the rear frame. The rear wheel has a large width in order to limit the banking of the rear frame about the coupling shaft. The frame assembly also includes a seat frame with a front portion which is swingable about a vertical shaft mounted on the front frame.
During cornering, the front frame is controlled to bank, whereas the rear wheel, which does not bank, maintains contact with the road through a sufficiently large contact area. The seat frame is swung laterally with the banking front frame to balance the centrifugal force acting on the motorcycle during the turn, thus allowing the motorcycle to run at an increased speed through the turn.
Since the front frame is tiltable with respect to the rear frame and the seat frame is swingable about the vertical shaft on the front frame, it is desirable that the front frame be prevented from making unwanted banking motion and that the seat frame be prevented from swinging unnecessarily while the motorcycle is running.
When the motorcycle makes a turn or corners, the rider's body tilts laterally with the front frame and the seat frame. To assist the rider in tilting his or her body, the motorcycle has footsteps attached to the seat frame for the rider's feet to be placed thereon. Therefore, a gear shift pedal, for operating a transmission of a power unit on the motorcycle, and other foot-operated control pedals should preferably be located near the footsteps. If the transmission and other devices to be controlled by these control pedals are installed on the rear frame which does not bank, the control pedals and the controlled devices should be operatively connected so as not to interfere with the movement of the seat frame, which banks with the front frame and is swingable about the vertical shaft.
For driving the motorcycle efficiently at a high speed, large drive forces from the rear drive wheel should effectively be transmitted to the front frame which is tiltable with respect to the rear frame.